Posting it on your Google+ profile will register as a +1 on the button.
Posting on my google+ as a way to +1 a page is a terrible user experience.
Edit: I can't find a way to view all of my +1s. Google needs to hire some new UX people.
Edit2: I found it. You have to go to your profile and there is a +1's tab/button that will show all of your +1s. Oddly 'search plus your world' seems broken. I have this page +1'd
http://www.guardian.co.uk/environment/2012/jun/01/north-caro...
If I search for 'north carolina sea level rise' I would expect my +1 to show up. It doesn't.
No normal human being will take the time to figure out this maze of google spaghetti
I can make my way through this maze, but I have no idea how they expect normal people to put all these pieces together.